A chameleon-like drive that shifts its nature primarily based on its surroundings may clarify a significant physics quandary: how the mysterious substance known as darkish power is compelling the cosmos to broaden sooner and sooner. However a brand new experiment casts doubt on some chameleon theories, researchers report August 25 in Nature Physics.
The chameleon drive can be a fifth sort of drive past the fundamental 4: gravitational, sturdy, weak and electromagnetic. And like a chameleon altering its colours, the hypothetical fifth drive would morph relying on the density of its environment. In dense environments like Earth, this fifth drive can be feeble, camouflaging its results. Within the sparseness of area, the drive can be stronger and long-ranged.
This drive would end result from a chameleon discipline — an addition to the recognized fields in physics, reminiscent of electrical, magnetic and gravitational fields. A chameleon discipline with these morphing properties may drive the accelerating growth of the universe with out disagreeing with measurements on Earth.
Nevertheless it’s a problem to suss out such a changeling drive. On Earth, says astrophysicist Jianhua He of Nanjing College in China, “it’s very, very tiny. That’s probably the most troublesome half.”
So He and colleagues designed a detector to seek for a refined fifth drive. A wheel with plastic movies connected spins previous one other movie sitting on a magnetically levitated piece of graphite. If a chameleon drive actually exists, the movies spinning by would trigger a periodic drive on the levitating plastic, pulling it up and down. (Gravity additionally acts this fashion, however due to the system’s design, it must be a lot weaker than a chameleon drive.)
The workforce was capable of rule out a class of chameleon theories. Sooner or later, the researchers hope to enhance their outcomes by chilling their system to permit for extra delicate measurements.
